The present invention is generally related to recording systems for digital video and other data, and in particular, provides structures and methods for positioning a hard disk cartridge within a disk drive, especially for manually inserting the cartridge into the drive.
Video Cassette Recorders ("VCRs") dominate the consumer video market, due in part to their combination of low cost and recording capabilities. VCR analog magnetic tape recording cassettes can be used to record, play-back, and store video images in a format which is well adapted for use with existing analog television signals. The ability to record allows consumers to use the standard VHS VCR to save television shows and home movies, as well as for play-back of feature films.
The structure of VCR systems and recording media are adapted to record and archive existing television signals. Specifically, a large amount of analog data is presented on a standard television screen during a standard length feature film. VCR systems record this analog data using analog recording media. The VCR recordings can be removed from the recording/play-back equipment for storage, thereby minimizing the system costs when large numbers of movies are stored.
While VCR systems successfully provide recording and archive capabilities at low cost, these existing consumer video systems have significant disadvantages. For example, accessing selected portions of a movie stored on a VCR tape can be quite slow. In particular, the cassette must be rewound to the beginning of the movie between each showing, which can involve a considerable delay. Additionally, transferring data to and from the tape takes a substantial amount of time. Although it would be beneficial to provide high speed accessing and transfer of the video data, this has remained a secondary consideration, as movies are typically recorded and played by the consumer in real time. Alternatives providing faster access are commercially available (for example, optical video disks), but these alternatives generally have not been able to overcome the VCR's low cost and recording capabilities.
Recent developments in video technology may further decrease the VCR's advantages over alternative systems. Specifically, standard protocols have recently been established for High Definition TeleVision ("HDTV") signals. The digital data presented in a single HDTV feature film using these protocols can represent a substantial increase over existing VCR system capacities. While digital video cassette tapes are available, these modified versions of existing analog VCR systems do not appear to have sufficient storage capacity for a feature film in all of the proposed HDTV formats. Optical disks can accommodate these larger quantities of digital data. Unfortunately, despite many years of development, a successful low cost optical recording system has remained an elusive goal.
Personal computer magnetic data storage systems have evolved with structures which are quite different than consumer video storage systems. Modern personal computers often include a rigid magnetic disk which is fixed in an associated disk drive. These hard disk drive systems are adapted to access and transfer data to and from a recording surface of the disk at high speeds. It is generally advantageous to increase the total data storage capacity of each hard disk, as the disks themselves are typically fixed in the drive system. Hence, much of the data that is commonly used by the computer is stored on a single disk.
The simplicity provided by such a fixed disk drive system helps maintain overall system reliability, and also helps reduce the overall storage system costs. Nonetheless, removable hard disk cartridge systems have recently become commercially available, and are now gaining some acceptance. While considerable computer data can be stored using these removable hard disk cartridge systems, their complexity, less than ideal reliability, and cost has limited their use to selected numbers of high-end personal computer users.
One particular disadvantage of known removable hard disk computer storage systems is the complexity of the structure used to align the removable cartridge with the surrounding disk drive. The disk generally spins within the cartridge, and a data transfer head of the drive is selectively positioned along the recording surface of the rotating disk. To engage and hold the cartridge housing with sufficient accuracy to accommodate these moving parts, known removable disk drive housing generally incorporate complex pins, cams, or other actuated support structures. The disk is often rotated by a spindle drive member which has to translate axially to engage a hub of the disk, further complicating the drive mechanism. Not only do these movable structures increase the complexity and cost of the disk drive system, failure of the actuation mechanisms could result in misalignment of the cartridge and housing. Such failures may decrease the overall reliability of the system, and may also result in damage to the disk drive components, or to the recording media.
In light of the above, it would be desirable to provide improved data storage systems, devices, and methods for storing video and other data. It would be particularly desirable if these improved systems, devices and methods were adapted for digital video data such as the new HDTV protocols, and had the ability to record, archive, and access digital feature films with good reliability and at a low system cost. It would be especially desirable to provide alternative cartridge positioning and support structures capable of providing the desired alignment between the cartridge and the associated disk drive, but without having to resort to the complex actuated holding mechanisms of known removable hard disk drives.